Aptose to Report Fourth Quarter and Full Year 2022 Financial Results and Hold Conference Call on Thursday, March 23, 2023

SAN DIEGO and TORONTO, March 09, 2023 (GLOBE NEWSWIRE) — Aptose Biosciences Inc. (Nasdaq: APTO; TSX: APS), a clinical-stage precision oncology company developing highly differentiated oral kinase inhibitors to treat hematologic malignancies, will report financial results for the fourth quarter and full year ended December 31, 2022, on Thursday, March 23, 2023, after the close of the market, and provide a corporate update. Conference Call & Webcast: Date:   Thursday, March 23, 2023  Time:  5:00 PM ETAudio Webcast Only:linkQ&A Participant Registration Link*:here(https://register.vevent.com/register/BI9394078d0ea14714aca591ffe06992f1) *Analysts interested in participating in the question-and-answer session will pre-register for the event from the participant registration link above to receive the dial-in numbers and a personal PIN, which are required to access the conference call. They also will have the option to take advantage of a Call Me button and the system will automatically dial out to connect to the Q&A session. The audio webcast also can be accessed through a link on the Investor Relations section of Aptose’s website here. A replay of the webcast will be available on the company’s website for 30 days. The press release, the financial statements and the management’s discussion and analysis for the quarter and year ended December 31, 2022 will be available on SEDAR at www.sedar.com and EDGAR at www.sec.gov/edgar.shtml. About Aptose Aptose Biosciences is a clinical-stage biotechnology company committed to developing precision medicines addressing unmet medical needs in oncology, with an initial focus on hematology. The Company’s small molecule cancer therapeutics pipeline includes products designed to provide single agent efficacy and to enhance the efficacy of other anti-cancer therapies and regimens without overlapping toxicities. The Company has two clinical-stage oral kinase inhibitors under development for hematologic malignancies: tuspetinib (HM43239), an oral, myeloid kinome inhibitor being studied as monotherapy and in combination therapy in the APTIVATE international Phase 1/2 expansion trial in patients with relapsed or refractory acute myeloid leukemia (AML); and luxeptinib (CG-806), an oral, dual lymphoid and myeloid kinome inhibitor in a Phase 1 a/b trial in patients with relapsed or refractory B cell malignancies who have failed or are intolerant to standard therapies, and in a separate Phase 1 a/b trial in patients with relapsed or refractory AML or high risk myelodysplastic syndrome (MDS). For more information, please visit www.aptose.com. For further information, please contact: Aptose Biosciences Inc.  LifeSci Advisors, LLC Susan Pietropaolo Dan Ferry, Managing DirectorInvestor Relations  617-430-7576201-923-2049  [email protected]@aptose.com